CN110894924A

CN110894924A - Embedded down lamp and radar system

Info

Publication number: CN110894924A
Application number: CN201910869563.7A
Authority: CN
Inventors: 李浩骏; 黄颂康
Original assignee: Infineon Technologies AG
Current assignee: Infineon Technologies AG
Priority date: 2018-09-13
Filing date: 2019-09-16
Publication date: 2020-03-20
Anticipated expiration: 2039-09-16
Also published as: CN110894924B; EP3624568B1; US20200091617A1; US11183772B2; EP3624568A1; US20220037801A1

Abstract

Embodiments of the present disclosure relate to embedded downlights and radar systems. In an embodiment, a downlight includes a plurality of Light Emitting Diodes (LEDs) disposed in a housing of the downlight; and millimeter wave radar. The millimeter wave radar includes an antenna provided in the housing; a controller configured to detect the presence of a person in a field of view of the millimeter wave radar, determine a direction of movement of the detected person, and generate log data based on the direction of movement of the detected person; and a wireless module configured to transmit the log data to a wireless server.

Description

Embedded down lamp and radar system

Cross Reference to Related Applications

This application is related to co-pending U.S. patent application No. 16/130,507 filed on 13.9.2018, which is hereby incorporated by reference.

Technical Field

The present invention relates generally to an electronic system and method, and, in particular embodiments, to an embedded lamp and radar system.

Background

In modern society, light bulbs are ubiquitous. Efficient bulbs are often required. Light Emitting Diode (LED) bulbs are bulbs that use LEDs to generate light. LED light bulbs are more efficient than conventional incandescent lamps, which use a incandescent filament heated by an electric current to produce light. LED bulbs are also more efficient than fluorescent lamps. In addition to being more efficient (or due to being more efficient), LED light bulbs generate less heat than conventional light bulbs.

LED light bulbs use LED drivers to drive LEDs. The circuitry of the LED driver and associated light fixture typically converts AC power (e.g., 60Hz, 120V), for example, from the power grid, to DC power and delivers a DC voltage or PWM signal to the LEDs to generate light. While some LED bulbs cannot be dimmed, some LED bulbs may be dimmed by modulating the PWM signal to adjust the intensity of light generated by the LEDs.

Some LED bulbs and fixtures include an LED driver inside the fixture. Other LED bulbs and fixtures include LED drivers external to the fixture.

There are various kinds of light fixtures. For example, downlights are light fixtures that are typically mounted in a hollow opening in a ceiling, and concentrate the generated light in a downward direction. Some downlights use LED bulbs to generate light. For example, fig. 1 shows a conventional downlight 100 that uses LEDs to generate light. Downlights are popular in shopping centers, offices, industrial locations, airports, and other locations.

Disclosure of Invention

According to an embodiment, a downlight includes a plurality of Light Emitting Diodes (LEDs) disposed in a housing of the downlight; and millimeter wave radar. The millimeter wave radar includes an antenna provided in a housing; a controller configured to detect the presence of a person in a field of view of the millimeter wave radar, determine a direction of movement of the detected person, and generate log data based on the direction of movement of the detected person; and a wireless module configured to transmit the log data to a wireless server.

According to an embodiment, a method comprises: detecting the presence of a person in a field of view of a millimeter wave radar embedded in a housing of the downlight; determining a direction of movement of the detected person; generating log data based on the detected moving direction of the person; and transmitting the log data to the server using a wireless transmission channel.

According to an embodiment, a method comprises: determining whether a person is entering or leaving a building using a millimeter wave radar embedded in a respective housing of a respective down lamp of a plurality of down lamps located at an entrance to the building; calculating a first number of people entering the building during a first time period; calculating a second number of people leaving the building during the first time period; and controlling the brightness of light generated by the plurality of downlights based on the first number of people and the second number of people.

Drawings

For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which

FIG. 1 illustrates a conventional downlight that uses LEDs to generate light;

FIG. 2 illustrates a conventional indoor infrared system for detecting persons at an entrance;

FIG. 3 shows a radar system according to an embodiment of the invention;

FIG. 4 illustrates a bistatic millimeter wave radar according to an embodiment of the present invention;

FIG. 5A illustrates a monostatic millimeter wave radar according to an embodiment of the invention;

FIG. 5B shows a flow diagram of an embodiment method for detecting a person crossing a plane, in accordance with an embodiment of the invention;

FIG. 5C shows a flow diagram of an embodiment method for detecting a person crossing a plane, in accordance with an embodiment of the invention;

FIG. 6A illustrates a cross-sectional view of the monostatic millimeter wave radar of FIG. 5A in accordance with an embodiment of the invention;

FIGS. 6B and 6C illustrate top and bottom views, respectively, of the monostatic millimeter wave radar of FIG. 6A in accordance with an embodiment of the invention;

FIG. 6D illustrates a schematic diagram of the monostatic millimeter wave radar of FIG. 6A, according to an embodiment of the invention;

FIGS. 7A and 7B show perspective and top views, respectively, of an LED downlight with an embedded millimeter wave radar according to an embodiment of the present invention;

FIGS. 7C and 7D show schematic diagrams of top and cross-sectional views, respectively, of the LED downlight of FIGS. 7A and 7B, according to an embodiment of the present invention;

fig. 7E shows an electrical schematic diagram of the circuitry of the LED downlight of fig. 7A to 7D, according to an embodiment of the present invention;

FIGS. 7F and 7G show perspective views of portions of circuitry inside the housing of the LED downlight of FIGS. 7A-7E, according to an embodiment of the present invention; and

fig. 8A shows a top view of a schematic of a building including a plurality of the LED downlights of fig. 7A-7G, according to an embodiment of the invention;

FIG. 8B illustrates a Graphical User Interface (GUI) that may be used to access the wireless server of FIG. 8A according to an embodiment of the present invention;

FIG. 9 shows a top view of a schematic of a building including a plurality of the LED downlights of FIGS. 7A-7G according to another embodiment of the invention; and

fig. 10 shows the LED downlight of fig. 7A to 7G mounted on a ceiling according to an embodiment of the present invention.

Corresponding reference numerals and symbols in the various drawings generally refer to corresponding parts unless otherwise indicated. The drawings are drawn to clearly illustrate the relevant aspects of the preferred embodiments and are not necessarily drawn to scale. To more clearly illustrate certain embodiments, letters indicating changes in the same structure, material, or process steps may follow the figure number.

Detailed Description

The making and using of the disclosed embodiments are described in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention.

The following description sets forth various specific details in order to provide a thorough understanding of several example embodiments in accordance with the present description. Embodiments may be obtained without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the embodiments. Reference in the specification to "an embodiment" means that a particular configuration, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, phrases such as "in one embodiment" that may be present in various points of the specification do not necessarily all refer to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

The invention is described with reference to embodiments in a specific context, an LED tube lamp having a millimeter wave radar and being implemented in a building, such as a shopping mall. Some embodiments may be used with other types of downlights (such as non-LED based downlights) as well as with street lights and other types of lights.

In an embodiment of the present invention, the LED downlight counts the number of people entering and leaving the entrance of the building by using a millimeter wave radar embedded in the LED downlight. The direction of the person (e.g. into or out of the entrance) is determined by using the ranging information, such as by using range FFT. Data (e.g., personnel detection logs or raw data) is transmitted from one or more LED downlights to a wireless server using a Low Power Wide Area Network (LPWAN) protocol. The wireless server makes the data available to various electronic devices (e.g., via the internet). The wireless server also controls the LED downlight based on information received from the LED downlight.

In some embodiments, the wireless server also interacts with additional sensors (e.g., temperature sensors, pressure sensors, etc.) and additional systems (e.g., air conditioners, security systems, etc.) of the building. For example, in some embodiments, the wireless server receives data from these sensors and LED downlights and controls such systems (e.g., air conditioners, security systems, etc.) based on the data received from the sensors and LED downlights. In some embodiments, the wireless server receives data from the sensors and the LED downlight, and controls the LED downlight based on the data received from the sensors and the LED downlight.

Some embodiments perform data mining and data processing on data collected by the LED downlights and by additional sensors (e.g., the number of people inside the building) to predict behavior (e.g., using artificial intelligence and machine learning algorithms), and adjust the LED downlights and other systems based on such predictions.

In many applications, from stores and shopping malls to factories and airports, it is often desirable to monitor the flow of people. For example, fig. 2 shows a conventional indoor infrared system 200 for detecting a person at an entrance 202. Specifically, infrared system 200 includes an infrared Transmitter (TX)204 and an infrared Receiver (RX) 206.

During normal operation, infrared TX 204 transmits infrared signal 208 to infrared RX 106. When a person crosses an entrance 202 (e.g., of a store or shopping mall), the person blocks the infrared signal 208, causing the infrared RX 206 to stop receiving the infrared signal 208. Infrared system 200 interprets the interruption of infrared signal 208 as a person entering or exiting portal 202. Such an event may trigger an action, such as a ringing.

Although the system 200 detects people as they cross the portal 202, the system 200 does not detect the direction in which the people are traveling (e.g., entering or leaving a store or shopping mall portal). It is often necessary to detect the direction in which the person is travelling. For example, a landlord of a shopping mall may determine the number of people inside the shopping mall by counting the number of people entering the shopping mall and subtracting the number of people leaving the shopping mall. This information can be used for a variety of purposes including security purposes, improving the shopping mall experience, and creating marketing materials.

Conventional camera-based systems may be used to perform people counting. For example, a camera-based system may use a video camera to capture images of people entering a shopping mall. Each video camera may send such images to a centralized location (e.g., a server) using WiFi. The server may then use a facial recognition algorithm to count the number of people entering the shopping mall.

Embodiments of the present invention detect a person (e.g., moving, standing, lying down, etc.) and a direction of movement of the person (e.g., entering or leaving a building) using millimeter wave radar and signal processing techniques such as doppler processing, Frequency Modulated Continuous Wave (FMCW) processing, or Frequency Shift Keying (FSK). For example, fig. 3 shows a radar system 300 according to an embodiment of the invention. Radar system 300 includes millimeter-wave radar 302 and processor 304.

During normal operation, millimeter-wave radar 302 transmits a plurality of radiated pulses 306 (such as chirps) to scene 308. The transmitted radiation pulse 306 is reflected in an object of the scene 308. The reflected radiation pulses (not shown in fig. 3), also referred to as echo signals, are detected by millimeter wave radar 302 and processed by processor 304 to detect, for example, a person and a direction of movement of the person.

Objects in scene 308 may include static people, such as lying person 310; persons exhibiting low and infrequent movement, such as standing person 312; and moving people, such as running or walking

people

314 and 316. The objects in the scene 308 may also include static objects, such as furniture and periodic motion devices (not shown). Other objects may also be present in the scene 308.

The processor 304 analyzes the echo data using signal processing techniques to detect the person and the direction of movement of the person.

The processor 304 may be implemented as a general purpose processor, a controller, or a Digital Signal Processor (DSP). In some embodiments, processor 304 may be implemented as a custom Application Specific Integrated Circuit (ASIC). In some embodiments, processor 304 includes multiple processors, each having one or more processing cores. In other embodiments, processor 304 comprises a single processor with one or more processing cores.

Millimeter-wave radar 302 includes millimeter-wave radar sensor circuitry and one or more antennas. Millimeter wave radar transmits and receives signals in the range of 20GHz to 122 GHz. Alternatively, frequencies outside this range may also be used. Millimeter-wave radar 302 may be implemented, for example, in a monostatic configuration or a bistatic configuration.

An advantage of implementing millimeter-wave radar 302 in, for example, a bistatic configuration is that radar system 300 is enabled to detect and track the location of a person as the person moves across the field of view of millimeter-wave radar 302. For example, FIG. 4 illustrates a bistatic millimeter wave radar 404 according to an embodiment of the present invention. As shown in fig. 4, bistatic millimeter wave radar 404 is located in ceiling 408. Personnel 412 are located in scene 402 above floor 410 and within the field of view of bistatic millimeter wave radar 404. Bistatic millimeter-wave radar 404 may report and track location information for person 412 using elevation component 418, azimuth component 416, and distance component 415. Accordingly, bistatic millimeter-wave radar 404 is advantageously able to determine the direction in which person 412 is moving, whether person 412 is entering or leaving the entrance (e.g., if bistatic millimeter-wave radar 404 is located at the entrance), and count how many persons have entered and/or left the entrance. Bistatic millimeter-wave radar 404 is also advantageously capable of determining the speed of movement of the person, whether the person is lying or standing still, and other parameters associated with the physical characteristics and movement of the person.

An advantage of implementing millimeter-wave radar 302 in, for example, a monostatic configuration is that radar system 300 is enabled to detect a person as the person moves across the field of view of millimeter-wave radar 302 and determine whether the person is entering or leaving the entrance (e.g., if the radar is located at the entrance) using range information. For example, FIG. 5A illustrates a monostatic millimeter wave radar 504 according to an embodiment of the invention. As shown in fig. 5A, monostatic millimeter wave radar 504 is located in ceiling 408. Personnel 412 are located in scene 402 above floor 410 and within the field of view of monostatic millimeter wave radar 504.

Mono-ground millimeter wave radar 504 detects person 412 by using distance component 415 if, for example, angle α is 0 (where α is the angle between centerline 414 of the field of view of mono-ground millimeter wave radar 504 and vertical axis y), range component 415 is equal to height h when there is no object between mono-ground millimeter wave radar 504 and floor 410₁Whereas, when person 412 crosses the field of view of monostatic millimeter wave radar 504, range component 415 is equal to height h₂(the height of person 412). Thus, by detecting a change in height (from h)₁To h₁-h₂And go back to h₁) It may be detected that person 412 has crossed the field of view of the monostatic millimeter wave radar.

If angle α is greater than 0 ° (e.g., between 5 ° and 15 °, such as 10 °), then the direction in which person 412 is moving may be determined₁Cos (α). when the person 412 is moving from right to left in the x-direction (as shown in FIG. 5A), the distance component 415 may suddenly decrease when the person 412 first enters the field of view of the monostatic millimeter wave radar 504, and then the distance component 415 gradually decreases when the person 412 moves from right to left₁Cos (α). in some embodiments, movement from right to left in the x-direction may correspond to the person 412 entering the building.

As person 412 moves from left to right in the x-direction, person 412 initially enters the field of view of monostatic millimeter wave radar 504, initially at h₁Range component 415 at cos (α) may suddenly decrease, and then range component 415 gradually increases as person 412 moves from left to right₁*cos(α)。

FIG. 5B illustrates a flow diagram of an embodiment method 510 for detecting a person crossing a plane, in accordance with an embodiment of the present invention. The following explanation assumes that method 510 is implemented by monostatic millimeter wave radar 504. However, other millimeter-wave radars, such as millimeter-wave radar 404, may implement method 510.

During step 512, the millimeter wave radar monitors the range toward the object in its field of view. If no object is crossing the field of view (where the field of view defines a plane dividing two sides, such as the left and right sides in FIG. 5A), the distance between the millimeter wave radar and the nearest object is equal to the distance to the floor. If it is determined during step 514 that the distance between the millimeter wave radar and the nearest object is similar to the distance to the floor (e.g., above a first threshold, such as 90% of the distance to the floor), then it is determined during step 516 that no person is crossing the plane, and the millimeter wave radar continues to monitor the distance during step 512.

If it is determined during step 514 that the distance between the millimeter wave radar and the nearest object is less than the distance to the floor (e.g., less than the first threshold), then the abruptness of the change in distance between the millimeter wave radar and the object is determined during step 518. If it is determined during step 518 that the change in distance between the millimeter wave radar and the nearest object is abrupt, then if it is determined during step 520 that the distance between the millimeter wave radar and the nearest object increases slowly and then abruptly returns to the distance to the floor, it is determined during step 522 that the person has crossed the plane in a first direction (e.g., from left to right in FIG. 5A). If not, it is determined during step 524 that the distance between the millimeter wave radar and the nearest object decreases slowly and then suddenly returns to the distance to the floor, then it is determined during step 524 that the person has crossed the plane in a second direction (e.g., from right to left in FIG. 5A). If not, the millimeter wave radar determines that no personnel are crossing during step 516.

The abrupt change in the distance includes, for example, a change in the distance between the millimeter wave radar and the detected object, which is obtained by subtracting a distance of, for example, 70% of the typical height of a person from the distance between the millimeter wave radar and the floor and the distance between the millimeter wave radar and the floor. Typical heights of a walking person may be between 4.5 feet and 6.5 feet, for example. In some embodiments, because the change in distance is related to the height of the detected person and the height of the detected person is related to age, the age of the person being crossed may be estimated during step 528 based on the change in distance from the millimeter wave radar to the detected object.

In some embodiments, movement in the x-direction from right to left may correspond to a person 412 entering the portal, while movement in the x-direction from left to right corresponds to a person 412 leaving the portal. In other embodiments, movement from right to left in the x-direction may correspond to the person 412 leaving the portal, and movement from left to right in the x-direction may correspond to the person 412 entering the portal. It should be appreciated that movement of person 412 may include a z-component (i.e., movement in the z-axis) without affecting operation of monostatic millimeter wave radar 504. For example, the centerline 414 may define a plane (relative to the x-direction) that divides the left and right portions of the scene 402. Monostatic millimeter wave radar 504 may detect person 412 crossing from right to left or from left to right while allowing non-zero movement of person 412 in the y-axis or z-axis. Some embodiments may use millimeter wave radar with, for example, one transmitter antenna and two receiver antennas to improve the resolution of the direction of movement of the person.

Thus, monostatic millimeter wave radar 504 is advantageously capable of determining the direction in which person 412 is moving, whether person 412 is entering (recently) or leaving (exiting) a location such as an entrance (e.g., if monostatic millimeter wave radar 504 is located at an entrance), and counting how many persons have entered and/or left the location (e.g., the entrance) based on (e.g., based only on) distance information. By determining the direction of movement based on the range information (e.g., using range FFT), it can be determined how many people have entered or left the portal without performing complex calculations (e.g., determining the three-dimensional position of the people in the field of view or performing facial recognition image processing).

FIG. 5C shows a flowchart of an embodiment method 530 for detecting a person crossing a plane, in accordance with an embodiment of the present invention. The following explanation assumes that method 530 is implemented by monostatic millimeter wave radar 504. However, other millimeter-wave radars, such as millimeter-wave radar 404, may implement method 510.

During step 532, the millimeter wave radar transmits radar signals (e.g., chirps) to its field of view, receives echo signals, and determines frequency changes between the transmitted and received radar signals using doppler signal processing. A change in frequency between the transmitted and received radar signals is determined during step 534. In some embodiments, the change in frequency is determined during step 534 by measuring the phase difference between the I and Q signals from the mixer circuit receiving the echo signal.

If the change in frequency is below a predetermined threshold (e.g., no frequency change between transmitted and received radar signals), then it is determined during step 536 that no person is crossing the plane, and the millimeter wave radar continues to monitor for Doppler changes in step 532.

If the change in frequency is above a predetermined threshold, then if it is determined during step 536 that the frequency of the echo signal is lower than the transmitted radar signal, then it is determined during step 538 that the person has crossed the plane in a first direction (e.g., left to right in FIG. 5A). If it is determined during step 536 that the echo signal is of a higher frequency than the transmitted radar signal, then it is determined during step 540 that the person has crossed the plane in a second direction (e.g., from right to left in FIG. 5A).

In some embodiments, the speed of the person crossing the plane may be determined during step 542 based on the magnitude of the change in frequency, for example determined in step 534.

In some embodiments, method 530 may be advantageously implemented using processing complexity low enough to be implemented locally within millimeter wave radar 504.

Some embodiments may combine

methods

510 and 530 to, for example, improve the accuracy of human detection or other movement parameters. For example, some embodiments of aspects of the combining

methods

510 and 530 may adjust the threshold based on the magnitude of the frequency change (step 534) to determine what caused the abrupt change (step 518). As another non-limiting example, some embodiments may estimate the age of the person being crossed (step 528) and the speed of the person being crossed (step 542).

Having an angle α greater than 0 ° advantageously allows for determining whether a person is crossing a plane and the direction in which the person is crossing to be determined by a processing complexity that is lower than the processing complexity for computing the 3D position of the person when crossing the field of view of the millimeter wave radar, as described, for example, in fig. 5B and 5C.

Monostatic millimeter wave radar 504 may transmit raw data (e.g., range/time information) or processed data (e.g., including, for example, at time t) to a central location₀A log of one or more persons entering/leaving, or for example at a time t₀To time t₁The number of people entering and/or leaving during a time period). In some embodiments, because the amount of data transmitted to the central location by the monostatic millimeter wave radar 504 is relatively small (e.g., log data), LPWAN protocols such as SigFox, NBIoT, or LoRa may be used to transmit data from the monostatic millimeter wave radar 504 to the central location.

Monostatic millimeter wave radar 504 may be calibrated to optimize a particular height h₁The operation of (2). For example, some embodiments adjust the transmission power of the transmitter so that it has sufficient power to detect personnel at the height of the installation, while avoiding saturation of the receiver that receives the echo signal. For example, a first test signal may be transmitted toward the field of view without personnel crossing (e.g., an empty floor) to determine an optimal intensity. For example, the first test signal may have chirps transmitted at different intensities. The echo signal may be analyzed to select an intensity that does not saturate the receiver while still using the optimal dynamic range.

In some embodiments, a second test signal (which may be equal to the first test signal) may be used when the tester is crossing a plane to determine the detection threshold. For example, a person who is far from the millimeter wave radar tends to generate a weak reflected signal. The detection threshold based on the strength of the received signal may be adjusted to allow identification of the person from the noise.

The millimeter wave radar whose calibration is to be optimized for a particular altitude advantageously improves the signal-to-noise ratio (SNR), which helps to reduce the number of false positive and false negative person detections.

In some embodiments, the calibration process may be initiated remotely (e.g., via LPWAN). In some embodiments, the signal processing associated with selecting the best parameters may be performed locally. For example, the test signal and the calibration step may be installed in the millimeter wave radar in advance.

In some embodiments, during step 534, the change in frequency is determined by measuring the phase difference between the I and Q signals from the mixer circuit receiving the echo signal.

In some embodiments, a single monostatic millimeter wave radar design is advantageously suitable for operation in different areas, e.g., different entrances having ceilings of different heights, entrances to rooms or stores inside a building, locations inside a building (e.g., not entrances), and so forth.

In some embodiments, monostatic millimeter wave radar 504 may be dynamically calibrated. In other words, calibration may be triggered by wirelessly transmitted commands during normal operation.

For example, in some embodiments, a ceiling-mounted millimeter wave radar with a field of view at an angle α (e.g., between 5 ° and 15 °, such as 10 °) is capable of detecting people and people movement (e.g., direction of movement) over a range of 10 meters or more along the x-axis, as compared to conventional systems (such as passive infrared systems or ultrasound-based systems) having a typical coverage range of the x-axis of less than 4 meters.

FIG. 6A illustrates a cross-sectional view of monostatic millimeter wave radar 504 according to an embodiment of the invention. Millimeter-wave radar 504 includes die 608, ball 606, high frequency stack 604, and antenna 602. For example, millimeter wave radar 504 may be implemented as described in U.S. patent No. 9,935,065 filed in the united states at 21/12/2016, patent publication No. 2016/0178730 filed at 30/11/2015, and U.S. patent publication No. 2018/0074173 filed at 30/11/2015, the contents of which are incorporated herein by reference in their entirety.

As shown in fig. 6A, millimeter wave radar 504 is implemented in a monostatic configuration, where the same antenna 602 is integrated in the same package and used for both the Transmitter (TX) and Receiver (RX) modules. Implementing millimeter-wave radar 504 in a single configuration has the advantage of a small footprint (e.g., in a device or system).

The antenna 602 is coupled to the die 608, e.g., using conductive pillars 603. In some embodiments, conductive post 603 is part of antenna 602 and is made of the same material as antenna 602. In other embodiments, the antenna may be fed remotely, such as by electromagnetic coupling.

For example, the high frequency stack may be a RO 4350 stack from Rogers Corporation, a Megtron 6 or 7 stack from Panasonic, an HL972 or HL 872 stack from Mitsubishi. Other high speed stacks may also be used.

Balls 606 are used to connect die 608 to external circuitry. Some embodiments may implement a pad rather than a ball. Other connectors may also be used.

Die 608 includes millimeter-wave radar sensor circuitry (not shown). Millimeter-wave radar sensor circuitry may transmit and receive signals in the GHz range via antenna 602. For example, some embodiments may transmit and receive signals such as chirps in frequency bands allocated around frequencies such as 95GHz, 120GHz, 140GHz, and/or 240GHz and/or other frequencies in a range between about 95GHz and about 240 GHz. Other embodiments may transmit and receive signals such as chirps in the 20GHz to 122GHz range. Other embodiments may transmit and receive signals such as chirps at frequencies above 240 GHz. Other frequencies and frequency ranges are also possible.

In some embodiments, the millimeter wave radar sensor circuit processes echo signals received through the use of Band Pass Filters (BPFs), Low Pass Filters (LPFs), mixers, Low Noise Amplifiers (LNAs), and Intermediate Frequency (IF) amplifiers in a manner known in the art. The echo signal is then digitized for further processing using one or more analog-to-digital converters (ADCs). Other implementations are also possible.

Millimeter-wave radar 504 is capable of detecting the presence of an object (e.g., a person) in field of view 614 (i.e., a beam of millimeter-wave radar 504). As shown in fig. 6A, the object detection area varies based on the distance between the object and the antenna 602. As shown, the coverage diameter of the field of view 614 may increase with height. For example, corresponding to a distance r from the antenna 602₁Diameter d of₁Smaller than diameter d₂The diameter d₂Corresponding to the distance r to the antenna 602₂Wherein a distance r₂Greater than a distance r₁The coverage area is based on an angle β, which may be, for example, between 45 ° and 50 °, angles less than 45 ° or greater than 50 ° may also be used.

In some embodiments, millimeter-wave radar 504 determines the distance to the detected object using a range transform (such as a range FFT).

Fig. 6B and 6C show top and bottom views, respectively, of millimeter wave radar 504 according to an embodiment of the present invention. FIG. 6D shows a schematic diagram of millimeter-wave radar 504, in accordance with an embodiment of the present invention.

As shown, millimeter-wave radar 504 includes die 608 and antenna 602. Die 608 includes millimeter-wave radar sensor circuit 609, controller 618, and interface circuit 624. Millimeter-wave radar sensor circuit 609 includes front-end RF circuitry and mixed-signal circuit 616. The controller 618 includes a digital block 620 and a signal processing block 622.

The RF circuitry 614 is configured to transmit and receive radar signals (e.g., chirps). The RF circuit 614 includes a transmitter circuit 610, a receiver circuit 612. The RF circuit 614 is implemented in a single-base configuration.

The transmitter circuit 610 and the receiver circuit 612 may be implemented in any manner known in the art. The mixed-signal circuit 616 is configured to control the RF circuit 614 to transmit a signal (e.g., chirp) and receive an echo signal. The mixed signal circuit 616 is also configured to convert the RF signal to a digital signal, which is then transmitted to the controller 618.

Mixed signal circuit 616 may be implemented in any manner known in the art. For example, in some embodiments, mixed signal circuit 616 includes one or more Band Pass Filters (BPFs), Low Pass Filters (LPFs), mixers, Low Noise Amplifiers (LNAs), Intermediate Frequency (IF) amplifiers, Phase Locked Loops (PLLs), and analog-to-digital converters (ADCs).

The controller 618 is configured to process signals received from the millimeter wave radar sensor circuit 609 and transmit them to an external processor (not shown in fig. 6D). The controller 618 may be implemented in any manner known in the art, such as a general purpose controller or processor, an ASIC, or any other implementation. Controller 618 generally includes a digital block 620 for general control purposes (e.g., to control millimeter wave radar sensor circuit 609 and interface circuit 624) and a signal processing block 622 for processing signals received from millimeter wave radar sensor circuit 609. Digital block 620 may include a Finite State Machine (FSM).

The signal processing block 622 may be implemented with a Digital Signal Processor (DSP). In some embodiments, the signal processing block 622 implements a portion or all of the processor 204. In other embodiments, signal processing block 622 is not implemented, but rather raw data received from millimeter wave radar sensor circuit 609 is sent to an external processor (not shown) for further processing. In some embodiments, millimeter-wave radar sensor circuit 609 may be implemented as an FMCW sensor.

The interface circuit 624 is configured to transfer data from the controller 618 to an external processor (not shown). For example, interface 324 may be implemented using LPWAN (such as SigFox, NBIoT, or LoRa). In some embodiments, interface 624 is implemented using a wired communication protocol, such as Serial Peripheral Interface (SPI), inter-integrated circuit I2C, inter-IC source (I2S), or the like. Other communication protocols may be used, including other low data rate communication protocols.

Since radar signals of millimeter-wave radars (such as millimeter-

wave radars

302, 404, and 504) may penetrate materials such as plastic, millimeter-wave radars may be embedded into light fixtures, such as LED downlights with plastic covers. For example, fig. 7A and 7B show perspective and top views, respectively, of an LED downlight 700 with an embedded millimeter wave radar according to an embodiment of the present invention. Fig. 7C and 7D show schematic diagrams of a top view and a cross-sectional view, respectively, of an LED downlight 700 according to an embodiment of the present invention.

The LED downlight 700 includes a housing 702 and a housing 708. The housing 702 includes a plurality of LEDs 704 and a Printed Circuit Board (PCB) 706. The PCB706 includes a millimeter wave radar, such as the monostatic millimeter wave radar 504. The housing 708 includes a power connector 712 and supporting circuitry. An optional marker 710 may be included in the housing 702 as a reference for orientation (e.g., facing the inlet), as described below.

As shown in fig. 7A-7D, the LED704 surrounds the PCB 706. As shown, this arrangement allows for embedding the PCB706 without interfering with the light generated by the LEDs 704.

In some embodiments, PCB706 may include monostatic millimeter wave radar 504. in such embodiments, and as shown in FIG. 7D, PCB706 is disposed on a horizontal plane at an angle α. this arrangement allows for the implementation of angle α illustrated in FIG. 5A.

Optionally, indicia 710 are included to indicate the direction of the field of view 614. Such a marker is advantageous, for example, when an LED down lamp is installed (e.g., at an entrance), so that the millimeter wave radar determines which direction corresponds to a person entering the entrance and which direction corresponds to a person leaving the entrance.

The housing 702 is implemented with metal. The cover 711 is typically made of plastic. In some embodiments, the cover 711 may be implemented with glass.

Since the radar signal of the millimeter-wave radar can penetrate the material of cover 711, millimeter-wave radars such as millimeter-

wave radars

300, 404, and 504 can operate (e.g., detect a person and the movement of the person) while being embedded inside housing 702 and covered by cover 711.

Advantages of some embodiments include: the millimeter wave radar may be embedded within the housing of the light fixture without affecting aesthetics (e.g., the millimeter wave radar is not visible to a person crossing the plane). In some embodiments, the conventional housing of the light fixture has embedded millimeter wave radar without altering the housing shape. Thus, existing luminaire designs can be used to implement, for example, personnel detection and tracking functions. By embedding millimeter wave radar inside the luminaire, functions such as person detection and tracking can be performed using existing infrastructure and without the need to use separately installed dedicated sensors. Some embodiments may present the associated price/cost benefit to the user by avoiding expensive redesign of existing infrastructure (e.g., existing building infrastructure) or installation of additional dedicated hardware.

Fig. 7E shows an electrical schematic of circuitry 720 of LED downlight 700, according to an embodiment of the present invention. For example, portions of circuit 720 may be implemented in housing 708 and PCB 706. Circuit 720 includes power converter 724, controller 730, LED driver 726, millimeter wave radar 504, wireless module 734, and LED panel 728.

During normal operation, the circuit 720 is connected to an AC power source 722 using the connector 712. The power converter 724 converts AC power provided by the AC power source 722 into DC power. The DC power provided by power converter 724 is provided to controller 730 and millimeter wave radar 504. The LED driver receives power from the AC power source 722 and drives the LED panel 728 based on instructions received from the controller 730. Millimeter-wave radar 504 performs personnel detection, such as described with respect to fig. 5A, and transmits associated data to controller 730. Controller 730 receives data from millimeter-wave radar 504 (e.g., personnel detection data), LED driver 726 (e.g., LED status), and/or power converter 724 (e.g., telemetry data) and transmits such data to wireless module 734. The wireless module 734 transmits data from the controller 730 to the wireless server 736. The wireless module 734 may also receive data (e.g., instructions to dim the LEDs 704) from the wireless server 736 and transmit it to the controller 730.

The wireless module 734 may communicate with the wireless server 736 using LPWAN protocols such as SigFox, NBIoT, or LoRa. Using the LPWAN protocol has the advantage of being able to operate without user configuration. For example, in some embodiments, wireless module 734 is pre-configured during manufacturing. For example, when a user installs the LED downlight 700 in the ceiling near a mall entrance and provides power (e.g., using the connector 712), the wireless module 734 automatically (e.g., anonymously) establishes communication with the wireless server 736.

Modern LPWAN protocols (such as SigFox, NBIoT, or LoRa) use narrowband sub-gigahertz frequency communication channels, which are more efficient at penetrating metal ceilings of, for example, modern buildings, than existing gigahertz communication channels (such as Wifi or bluetooth). Thus, wireless communication using modern LPWAN protocols also has the advantage of allowing efficient wireless communication in modern buildings (e.g., with metal ceilings).

The AC power source 722 may be, for example, a 60Hz or 230Vrm 50Hz power source at 120 Vrms. Other AC power sources may be used.

The power converter 724 may be implemented in any manner known in the art. For example, the power converter 724 may be implemented as a Switched Mode Power Supply (SMPS). In some embodiments, power converter 724 may provide different voltage rails for different devices, such as a 3.3V rail for controller 730 and a 5V rail for millimeter wave radar 504. In some embodiments, the power converter 724 may include a charger circuit that charges a battery (not shown) configured to provide power if the AC power source 722 is temporarily unavailable.

LED driver 726 may be implemented in any manner known in the art. For example, the LED driver 726 may be implemented as a current-controlled SMPS. In some embodiments, the LED driver 726 is capable of dimming the LEDs 707. In some embodiments, LED driver 726 receives DC power instead of AC power.

Controller 730 may receive data from millimeter-wave radar 504, power converter 724, and/or LED driver 726. For example, controller 730 may receive data associated with person detection (e.g., a person entering or exiting an entrance, a count of persons within a time period, etc.) from millimeter wave radar 504. In some embodiments, the controller 730 may receive data associated with a state of the power grid (e.g., voltage and frequency of AC power provided by the AC power source 722) from the power converter 724 and/or the LED driver 726.

In some embodiments, the LED driver 726 may monitor parameters such as input voltage, power consumption of the LED panel 728, and the like. For example, the controller 730 may receive data of the monitored parameters from the LED driver 726 in real time. In some embodiments, the controller 730 may estimate characteristics of the LED panel 728 or one or more LEDs 704, such as LED failure or end-of-life warnings, lumens generated, etc., and transmit such information to the wireless server 736. In some embodiments, the controller 730 may transmit data received from the LED driver 726 to the wireless server 736, and the wireless server 736 may estimate parameters such as LED failure or end-of-life warnings, lumens generated, and the like.

In some embodiments, the controller 730 may receive data from an external source, such as other sensors (e.g., a light level sensor, a humidity sensor, a temperature sensor, etc.) coupled directly or, in some embodiments, wirelessly to the LED downlight 700. For example, in some embodiments, the LED downlight 700 includes an embedded temperature sensor (not shown) to monitor the temperature of the LEDs 704. For example, the temperature of the LED704 may indicate the luminosity produced by the LED 704.

Controller 730 may receive data and/or instructions from wireless server 736 and may use such information to dynamically adjust parameters of, for example, LED driver 726 and millimeter wave radar 504. For example, in some embodiments, the controller 730 may receive instructions from the wireless server 736 to dim (i.e., decrease brightness), dim (i.e., increase brightness), turn on or turn off one or more LEDs 704. As another non-limiting example, controller 730 may receive instructions from wireless server 736 to dynamically change the data collection method or processing technique of millimeter wave radar 504. In some embodiments, the controller 730 may dynamically receive recalibration instructions from the wireless server 736 to optimize operation at a particular altitude, for example. Controller 730 may control, for example, LED driver 726 and millimeter wave radar 504 according to instructions received from wireless server 736.

In some embodiments, controller 730 may dim, dim up, turn on, or turn off one or more LEDs 704 based on data from millimeter wave radar 504 and without relying on instructions from wireless server 736. For example, in some embodiments, such as in a store having a single entrance, the controller 730 may dim the LED704 when the number of people within (e.g., the store) (e.g., determined by subtracting the number of people leaving a location from the number of people entering the location) is below a threshold, such as 5 people. When the number of people inside the location increases above, for example, 10 people, the controller 730 may turn on the LED 704.

Controller 730 communicates with millimeter-wave radar 504, LED driver 726, and wireless module 734 using communication protocols known in the art. For example, some embodiments use wired communication protocols, such as SPI, I²C. I2S, universal asynchronous receiver-transmitter (UART), etc. Some embodiments use wireless communication protocols for such communication, such as bluetooth, WiFi, and the like.

The controller 730 may be implemented as a general purpose processor, a controller, or a Digital Signal Processor (DSP). In some embodiments, controller 730 may be implemented as a custom Application Specific Integrated Circuit (ASIC). In some embodiments, controller 730 includes multiple processors, each having one or more processing cores. In other embodiments, controller 730 comprises a single processor with one or more processing cores.

In some embodiments, controller 730 includes controller 618. In other embodiments, controller 618 is implemented separately from controller 730.

PCB706 includes millimeter-wave radar, such as millimeter-

wave radar

404 or 504, such as shown in fig. 6A-6D. In some embodiments, PCB706 includes a portion of a millimeter wave radar, such as a transmit/receive antenna, while other components of the millimeter wave radar are implemented elsewhere. PCB706 may be implemented in any manner known in the art. For example, the PCB706 may be implemented as a flexible PCB or a non-flexible PCB. PCB706 may be implemented with a combination of low dielectric constant material and FR 4. In some embodiments, PCB706 may be implemented with pure FR4 if carefully designed. Other types of materials may also be used.

The wireless server 736 may be a remote server. For example, in some embodiments, wireless server 736 is a server located several miles away from LED downlight 700, such as in a centralized server farm. In some embodiments, the wireless server 736 is connected to the cloud and can be accessed through a personal computer, smartphone, tablet, or other electronic device, for example, via the internet.

Advantages of some embodiments include: millimeter wave radars embedded in light fixtures may operate by using existing power connections. In some embodiments, it is advantageous to pre-configure the wireless communication channel for transmitting information from the millimeter wave radar (or other data source internal to the luminaire) to the wireless server or to provide instructions from the wireless server to control parameters of the luminaire, and to operate without human intervention. Thus, some embodiments advantageously exhibit plug-and-play capabilities. In other words, in some embodiments, a user installs a light fixture with embedded millimeter wave radar by connecting the light fixture to AC power, and after powering up, the user can access data (e.g., the number of people entering or leaving the entrance) collected by the millimeter wave radar by using an electronic device (e.g., a smartphone, a computer, or a tablet) without additional configuration of the light fixture. In some embodiments, the plug-and-play capability is extended to allow a user to control parameters of the light fixture, such as, for example, changing the brightness level of one or more LEDs.

Fig. 7F and 7G show perspective views of portions of circuitry inside housing 708, in accordance with an embodiment of the present invention. As shown in fig. 7F, the housing 708 includes a PCB 738. The PCB 738 includes the power converter 724, the controller 730 (not shown), and the wireless module 734 (not shown). As shown in fig. 7G, the housing 708 also includes a PCB 740 that includes the LED driver 726. Some embodiments may implement the circuitry inside housing 708 in a different manner (e.g., using a single PCB or more than two PCBs). For example, some embodiments may implement some of the circuitry shown in fig. 7F and 7G inside housing 702 (such as in PCB 706).

The LED downlight 700 includes a monostatic millimeter wave radar 504. In some embodiments, LED downlight 700 may be implemented with other types of millimeter-wave radars (e.g., millimeter-wave radar 404).

Fig. 8A shows a top view of a schematic of a building 802 including a system 800 according to an embodiment of the invention. System 800 includes a plurality of LED downlights 700 and a wireless server 836.

Building 802 includes a plurality of entrances 804. An LED downlight 700 is disposed in front of each inlet 804. As shown in fig. 8A, each LED downlight 700 is oriented toward a respective entrance 804, as indicated by optional indicia 710.

The wireless server 836 communicates with each LED downlight 700 using LPWAN protocols such as SigFox, NBIoT, or LoRa. When the LED downlight 700 is installed (e.g., power is provided to the LED downlight 700), each LED downlight 700 communicates with the wireless server 836. For example, in some embodiments, each LED downlight periodically transmits a log including each person detected, a timestamp of the person detected, and a direction of the person detected (e.g., into or out of the respective entrance).

In some embodiments, the wireless server 836 stores, for each sampling point (e.g., for each log record), a device id (to identify which LED downlight 700 is associated with the data), a timestamp (e.g., to identify the date and time of the detection period), the number of people approaching the entrance (e.g., entering the building 802), the number of people leaving the entrance (e.g., leaving the building 802), an entrance id (to identify the entrance, which may be derived from the device id), and a description field (e.g., such as "mini-bus entrance," "coffee shop entrance," etc.).

In some embodiments, each LED downlight 700 periodically reports to the wireless server 836 how many people entered/exited during the relevant time period. For example, each LED downlight 700 reports, e.g., every 5 minutes, how many people entered and exited during those 5 minutes. In other embodiments, each LED downlight 700 asynchronously reports to the wireless server 836 that a person has been detected entering/leaving the portal.

The wireless server 836 performs data management and stores the information received from each LED down lamp 700, for example, in the database 812. The wireless server 836 may also aggregate and process information from each LED downlight 700 and make it accessible to external electronic devices 810. For example, the wireless server may calculate how many people are inside the building 802 by adding all people entering the building 802 and subtracting all people leaving the building 802.

The wireless server 836 may also determine peak operating times (hours when the number of people is greatest), average number of people, and other metrics based on data collected from the LED downlight 700.

For example, the wireless server 836 may also determine the remaining life expectancy of each LED downlight 700. For example, the power consumption of an LED lamp decreases near the end of its life. The LED downlight 700 may monitor the power consumption of its associated LED704 to determine the end of life of the LED 704. Such information (e.g., power consumption and/or end-of-life estimates of the LEDs 704) may be transmitted to the wireless server 836, and the wireless server 836 may then alert the user to potential lighting interruptions. The wireless server 836 may also automatically compensate for the brightness reduction of the LED downlight near end-of-life by adjusting the brightness of such LEDs.

The wireless server 836 may also receive telemetry information (e.g., voltage and frequency of the AC power source 722) from each LED downlight 700 and make such data available to the user (e.g., via the electronic device 810). For example, telemetry information may also be used to confirm that an action, such as turning the LED downlight 700 on or off, was actually performed. As another example, the telemetry information may be used to confirm which dimming level is currently in operation (e.g., based on the power consumption of the LED panel 728).

The wireless server 836 may also control one or more LED downlights 700 based on information from each LED downlight 700 and information from the external device 810. For example, the wireless server 836 may dim the downlight 700 (e.g., by instructing the respective controller 730 using the LPWAN) when the number of people inside the building 802 (or a portion of the building 802) is below a threshold (e.g., 20 people). In some embodiments, the electronics 810 may be used to control one or more LED downlights 700. For example, a smartphone may be used to turn on, turn off, or change the brightness of one or more LED downlights 700, e.g., using an app in the smartphone.

For example, electronic devices 810 include personal computers, smart phones, and tablets. For example, the electronic device 810 may communicate with the wireless server 836 via the internet. For example, the electronic device 810 may access data contained in the wireless server 836 by logging into a website or using an app.

For example, the wireless server 836 may host data using a cloud computing platform (such as amazon web services, microsoft Azure, and google cloud platforms) and communicate with the electronic device 810 using apps and a website server (e.g., via the internet).

In some embodiments, the wireless server 836 may store historical data for one or more LED downlights 700, and use such data to predict behavior, and dynamically adjust the LED downlights 700 based on such predictions. For example, data mining techniques may be used to predict peak personnel traffic on locations on a particular date (e.g., a typical rainy saturday). This prediction may be used to dynamically adjust the dimming of the LED lamp 700. Such data and predictions may also be used, for example, to calculate previous power usage of the LED downlight 700 and estimate the expected power usage of the LED downlight 700. In some embodiments, Artificial Intelligence (AI) and machine learning algorithms may be used to optimize the dynamic control of the LED lamp 700.

The building 802 may be, for example, a shopping mall, an office building, or a factory. Other buildings, such as a residence, convention center, hotel, or other building may also be used. It should be understood that system 800 may also be implemented outside a building. For example, in some embodiments, system 800 may be implemented in a street light to determine, for example, the flow of people in a sidewalk. The form factor and other characteristics may be adapted to suit a particular application. For example, street lights may be designed to be weatherproof.

Advantages of some embodiments include: a building may implement a system such as system 800 by replacing an existing downlight with a downlight implemented according to an embodiment of the present invention. Since the LED downlight 700 operates by using an interface similar to a conventional downlight (e.g., a connector 712 that receives AC power from the grid), and incorporates millimeter wave radar inside the housing 702, some embodiments implement the system 800 in a building without compromising aesthetics and without requiring the installation of additional sensors or wiring. Some embodiments may reuse 100% of the existing infrastructure (e.g., wiring, ceiling pockets, etc.).

The advantage of using millimeter wave radar within a downlight is that a large coverage area (e.g., greater than 10 meters along the x-axis) is achieved, in part because the radar signal from the millimeter wave radar can penetrate the plastic. The ability to be dynamically calibrated advantageously allows the same model of downlight to be installed at different heights and under different conditions without affecting performance.

An additional advantage of using millimeter wave radar is that privacy issues associated with capturing and storing images of people are avoided, and facial recognition and other signal processing techniques are performed using these images.

Additional advantages of embodiments using LPWAN protocols are: for example, the wireless configuration step is avoided when installing downlights in a building. The use of LPWAN also has the advantage of allowing efficient wireless communication in modern buildings (e.g., buildings with metal ceilings) since LPWAN uses narrow-band sub-gigahertz frequency communication channels.

The LPWAN protocol may be used in part due to the relatively low data usage and low complexity of system 800. For example, people entering and leaving the portal may be counted locally in the LED downlight without complex radar signal processing, so that small log files/data (e.g., containing timestamps and detection directions) are transmitted periodically. Alternatively, data of the detected person may be transmitted to a wireless server for remote processing (e.g., remotely determining the person's direction of movement or filtering out noise).

Other advantages of some embodiments include: the person counting and monitoring may be performed automatically twenty-four hours a day and seven days a week. For example, people counting may last throughout the night and vacation without user intervention. Advantageously, autonomous interaction is possible between the wireless server and each downlight. In other words, the wireless server may dynamically adjust the state (e.g., on/off and dimmed states) of the downlight based on current person detection and historical data and estimated person traffic without user intervention.

In some embodiments, the wireless server 836 may process data from the LED downlight 700 using Artificial Intelligence (AI) and machine learning algorithms. For example, in some embodiments, correlations between people detections of various LED downlights 700 may be used to estimate people flow inside the building 802.

Although fig. 8A shows a single LED downlight 700 per portal, more than one LED downlight 700 per portal may be used. Some embodiments may also use LED downlights 700 inside a building (not just at the entrance) to, for example, monitor the flow of people inside the building.

Some embodiments may be adapted to detect other objects, such as automobiles. For example, some embodiments may use the system 800 implemented in a street light and/or traffic light to detect the number of moving cars, their associated speeds, and car congestion. As another example, some embodiments may determine the number of cars crossing a first intersection in a first direction and a second intersection following the first intersection in the first direction, for example, using millimeter wave radar embedded in traffic lights. Machine learning and AI algorithms may then be used to adjust the timing of the red and green lights of the first and second traffic lights, for example, to reduce car congestion.

Fig. 8B illustrates a Graphical User Interface (GUI)820 that may be used to access a wireless server 836 in accordance with an embodiment of the present invention. GUI 820 is a non-limiting example of a possible GUI that interfaces with wireless server 836. Other user interfaces (including other GUIs) are also possible. The GUI 820 includes a building map 824, a relative building traffic map 826, a rush hour map 832, a primary exit gate map 830, an energy savings map 822, and a total people traffic map 834.

The building map 824 is a map of the building 802, and shows in real time how many people enter and leave the building 802 at each entrance. For example, a bar next to the people symbol at each entrance may be used to indicate the number of people entering the building 802 (e.g., a bar toward the interior of the building 802 relative to the people symbol) and the number of people exiting the building 802 (e.g., a bar toward the entrance of the building 802 relative to the people symbol), where the number of bars indicates the number of people entering/exiting the building 802. In some embodiments, different colors may be used for the bars (e.g., red for in and blue for out).

The relative building traffic map 826 shows, for example, the relative passenger flow for each portal 804 that is the day (for clarity, only 4 portals are shown in the relative building traffic map 826). For example, the number of people symbols next to each portal represents the relative number of people entering and exiting a particular portal relative to other portals. In the example shown, all of the inlets shown have similar flow rates of personnel.

The rush hour plot 832 shows in each open circle, for example, the relative number of people flowing per hour in the respective inlet for the day (only 4 inlets are shown in this example for clarity), using a different shade of color. For example, each hollow circle is divided into 24 equal parts, and the darker color in a particular part of the 24 parts indicates a higher flow of people than the lighter color. In the example shown, the south inlet is higher in flow between 1 am and 10 am and 7 pm and 11 pm. The peak flow of people at east entry is 1 pm and 11 pm.

The primary exit gate diagram 830 shows the exit flow percentage for each entry on the day (only 4 entries are shown in this example for clarity). In the current example, for the day, 20.3% of people leave building 802 using the east entry, 36.2% of people leave building 802 using the south entry, 36.2% of people leave building 802 using the northeast entry, and 9.1% of people leave building 802 using the west entry.

Total people flow graph 834 shows the total number of people entering and leaving all entrances for the day. In the current example, 1000 people enter or leave the entrance of the building 802 on the same day.

The energy savings map 822 shows how much power is saved the day when traffic is low due to dimming the LED downlight 700. For example, the number of bulbs in the energy savings chart 822 indicates the number of kW saved due to dimming one or more LED downlights 700.

Some embodiments may integrate the system 800 with other types of sensors. For example, fig. 9 shows a top view of a schematic of a building 902 including a system 900 according to an embodiment of the invention. The system 900 includes a plurality of LED downlights 700, an internal temperature sensor 910, an external temperature sensor 912, a pressure sensor 906, and a wireless server 936.

The system 900 may operate in a similar manner as the system 800. However, system 900 can interact with additional sensors, such as

temperature sensors

910 and 912, and pressure sensor 906. Thus, the system 900 may advantageously use information from these additional sensors to dynamically adjust the LED downlight 700 and external systems, such as the air conditioner 916 and the security system 914. For example, some embodiments may use the current and/or estimated number of people within building 902, the current temperature of the building and/or the estimated temperature of the building (e.g., from interior temperature sensor 910), and the current temperature and/or the exterior temperature (e.g., from exterior temperature sensor 912) to control air conditioning 916.

As another non-limiting example, some embodiments may use the personnel detection capabilities of the downlight 700 and the pressure sensor 906 (located in the window 904) to trigger a security system (e.g., an alarm siren, police call, etc.). The security system may also dynamically adjust the brightness of the LED downlight 700 based on, for example, intrusion detection. For example, in some embodiments, the pressure sensor 906 may report to the wireless server 936 that the window is broken, and the wireless server may then turn on all of the LED downlights 700 at full brightness.

In some embodiments, the air conditioner 916 and alarm system 914 communicate with a wireless server 936 via the internet. In other embodiments, the air conditioner 916 and security system 914 communicate with the wireless server 936 using LPWAN protocols. Other communication channels may also be used.

In some embodiments, the wireless server 936 may implement data mining, AI, and machine learning algorithms to data associated with external sensors (in addition to data from the LED downlight 700). Other tasks, such as estimating power consumption associated with air conditioning, controlling air conditioning, alarm systems, and controlling other systems are also possible.

Advantages of some embodiments include: enabling seamless interaction of various systems (e.g., personnel detection, lighting, air conditioning, and security/alarm systems, etc.) without human intervention. In some embodiments, the wireless server advantageously serves as a gateway for intelligent buildings and allows for the addition of additional sensors and systems.

Fig. 10 shows a ceiling-mounted LED downlight 700 according to an embodiment of the present invention. As shown, two LED downlights 700 are used for security access inside a building (which may be inside an office building or airport, for example). As shown, the LED downlight 700 is aesthetically similar to other LED downlights at the entrance.

Example embodiments of the present invention are summarized herein. Other embodiments may also be understood from the entire specification and claims as filed herein.

Example 1. a downlight includes a plurality of Light Emitting Diodes (LEDs) disposed in a housing of the downlight; and a millimeter wave radar including: an antenna disposed in the housing, a controller configured to: detecting the presence of a person in a field of view of the millimeter wave radar, determining a direction of movement of the detected person, and generating log data based on the direction of movement of the detected person; and a wireless module configured to transmit the log data to a wireless server.

Example 2 the downlight of example 1, wherein the field of view of the millimeter wave radar comprises a centerline, the centerline being at an angle other than 0 ° with respect to the vertical axis.

Example 3 the downlight of one of examples 1 or 2, wherein the antenna is disposed in a Printed Circuit Board (PCB), wherein the plurality of LEDs are disposed around the PCB.

Example 4 the downlight of one of examples 1 to 3, wherein the antenna is integrated in an integrated circuit comprising the millimeter wave radar, and wherein the angle is between 5 ° and 15 °.

Example 5 the downlight of one of examples 1 to 4, wherein the antenna is disposed in a Printed Circuit Board (PCB), wherein the plurality of LEDs are disposed around the PCB, and wherein the PCB is in a plane having an angle with respect to a horizontal axis that is different from 0 °.

Example 6 the downlight of one of examples 1 to 5, wherein the angle is between 5 ° and 15 °.

Example 7 the downlight of one of examples 1 to 6, wherein the field of view of the millimeter wave radar determines a plane, and wherein the controller is configured to count the number of people crossing the plane and to transmit the count to the wireless server using the wireless module as part of the log data.

Example 8 the downlight of one of examples 1 to 7, wherein the field of view of the millimeter wave radar defines a plane, wherein the controller is configured to: determining a first direction of movement of the detected person when the person crosses the plane from the first side to the second side, and determining a second direction of movement of the detected person when the person crosses the plane from the second side to the first side, and wherein the log data comprises the direction of movement of the detected person.

Example 9 the downlight of one of examples 1 to 8, wherein the controller is further configured to: during a time interval, a first count of people crossing the plane from a first side of the plane to a second side of the plane is determined, a second count of people crossing the plane from the second side of the plane to the first side of the plane is determined, and the first count and the second count are transmitted to a wireless server using a wireless module as part of log data.

Example 10 the downlight of one of examples 1 to 9, wherein the controller is configured to periodically determine the first count and the second count, and to periodically transmit the first count and the second count to the wireless server.

Example 11 the downlight of one of examples 1 to 10, wherein the controller is further configured to determine a range component of the location of the detected person, and wherein the controller is configured to determine the direction of movement of the detected person based on the range component.

Example 12 the downlight of one of examples 1 to 11, further comprising a power converter configured to receive an AC supply voltage via the power connector; and an LED driver coupled to the plurality of LEDs, wherein the controller is configured to: receiving data from the wireless module, and controlling the LED driver based on the received data from the wireless module.

Example 13 the downlight of one of examples 1 to 12, wherein the controller is configured to adjust the luminosity of the plurality of LEDs by controlling the LED driver based on data received from the wireless module.

Example 14 the downlight of one of examples 1 to 13, wherein the LED driver is configured to determine a status of the AC supply voltage, and wherein the controller is configured to transmit the status of the AC supply voltage to the wireless server using the wireless module.

Example 15 the downlight of one of examples 1 to 14, wherein the wireless module is preconfigured such that the wireless module is configured to: when the power converter receives the AC supply voltage without user intervention, communicating with the wireless server.

Example 16 the downlight of one of examples 1 to 15, wherein the wireless module is configured to transmit data using a Low Power Wide Area Network (LPWAN) protocol.

Example 17 the downlight of one of examples 1 to 16, wherein the log data comprises a direction of movement of the person and a timestamp of the detected presence of the person.

Example 18 the downlight of one of examples 1 to 17, wherein the downlight is configured to be mounted at a ceiling having a first height to the floor, wherein the controller is configured to calibrate the millimeter wave radar to operate at the first height.

Example 19 the downlight of one of examples 1 to 18, wherein the controller is further configured to determine a change in frequency between a signal transmitted from the millimeter wave radar and a signal received by the millimeter wave radar, and wherein the controller is configured to determine the direction of movement of the detected person based on the change in frequency.

Example 20 the downlight of one of examples 1 to 19, wherein the millimeter wave radar is a monostatic millimeter wave radar.

Example 21 the downlight of one of examples 1 to 20, wherein the millimeter wave radar is configured to determine the location of the detected person using the elevation, azimuth and range components.

Example 22. a method, comprising: detecting the presence of a person in a field of view of a millimeter wave radar embedded in a housing of the downlight; determining a direction of movement of the detected person; generating log data based on the detected moving direction of the person; and transmitting the log data to the server using a wireless transmission channel.

Example 23 the method of example 22, further comprising: receiving log data from a plurality of downlights, the plurality of downlights including a downlight; determining a number of people inside the building based on log data from the plurality of downlights; and controlling the brightness of light generated by the plurality of downlights based on the determined number of people inside the building.

Example 24 the method of one of examples 22 or 23, further comprising: dimming the downlight when the determined number of people inside the building is below a threshold.

Example 25 the method of one of examples 22 to 24, further comprising: controlling operation of an air conditioner of the building based on the determined number of people inside the building.

Example 26 the method of one of examples 22 to 25, further comprising: receiving data from a pressure sensor located at a window or door of a building; and controlling the brightness of light generated by the downlight based on the light received from the pressure sensor.

Example 27. a method, comprising: determining whether a person is entering or leaving the building using millimeter wave radar embedded in respective housings of respective down lamps of a plurality of down lamps located at an entrance to the building; calculating a first number of people entering the building during a first time period; calculating a second number of people who left the building during the first period of time; and controlling the brightness of light generated by the plurality of downlights based on the first number of people and the second number of people.

Example 28 the method of example 27, further comprising: storing the first number and the second number in a database; and estimating the number of people entering or leaving the building based on data from the database.

Example 29 the method of one of examples 27 or 28, further comprising: storing the first number and the second number in a database; and determining peak hours of personnel traffic based on data from the database.

Example 30 the method of one of examples 27 to 29, further comprising: accessing a database using an electronic device via the internet; and displaying the peak hours in the electronic device.

While the present invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is therefore intended that the appended claims cover any such modifications or embodiments.

Claims

1. A downlight, comprising:

a plurality of Light Emitting Diodes (LEDs) disposed in a housing of the downlight; and

a millimeter wave radar, comprising:

an antenna disposed in the housing,

a controller configured to:

detecting the presence of a person in the field of view of the millimeter wave radar,

determining the direction of movement of the detected person, an

Generating log data based on the detected direction of movement of the person; and

a wireless module configured to transmit the log data to a wireless server.

2. A downlight according to claim 1, wherein the field of view of the millimeter wave radar comprises a centre line which is at an angle other than 0 ° to a vertical axis.

3. A downlight according to claim 2, wherein the antenna is provided in a Printed Circuit Board (PCB), wherein the plurality of LEDs are provided around the PCB.

4. A downlight according to claim 3, wherein the antenna is integrated in an integrated circuit comprising the millimeter wave radar, and wherein the angle is between 5 ° and 15 °.

5. A downlight according to claim 1, wherein the field of view of the millimeter wave radar determines a plane, and wherein the controller is configured to count the number of persons crossing the plane and to transmit the count to the wireless server using the wireless module as part of the log data.

6. A downlight according to claim 1, wherein the field of view of the millimeter wave radar defines a plane, wherein the controller is configured to: determining a first direction of movement of the detected person when the person crosses the plane from a first side to a second side, and determining a second direction of movement of the detected person when the person crosses the plane from the second side to the first side, and wherein the log data comprises the direction of movement of the detected person.

7. A downlight according to claim 6, wherein the controller is further configured to: during a time interval, determining a first count of people crossing the plane from the first side of the plane to a second side of the plane, determining a second count of people crossing the plane from the second side of the plane to the first side of the plane, and transmitting the first count and the second count to the wireless server using the wireless module as part of the log data.

8. A downlight according to claim 7, wherein the controller is configured to periodically determine the first count and the second count, and to periodically transmit the first count and the second count to the wireless server.

9. A downlight according to claim 1, wherein the controller is further configured to determine a range component of the location of the detected person, and wherein the controller is configured to determine the direction of movement of the detected person based on the range component.

10. A downlight according to claim 1, further comprising:

a power converter configured to receive an AC supply voltage via a power connector; and

an LED driver coupled to the plurality of LEDs, wherein the controller is configured to:

receiving data from the wireless module, an

Controlling the LED driver based on data received from the wireless module.

11. A downlight according to claim 10, wherein the controller is configured to adjust the luminosity of the plurality of LEDs by controlling the LED driver based on data received from the wireless module.

12. A downlight according to claim 10, wherein the LED driver is configured to determine a status of the AC supply voltage, and wherein the controller is configured to transmit the status of the AC supply voltage to the wireless server using the wireless module.

13. A downlight according to claim 10, wherein the wireless module is pre-configured such that the wireless module is configured to: communicating with the wireless server when the power converter receives the AC supply voltage without user intervention.

14. A downlight according to claim 1, wherein the wireless module is configured to transmit data using a Low Power Wide Area Network (LPWAN) protocol.

15. A downlight according to claim 1, wherein the log data comprises a timestamp of the direction of movement of the person and the detected presence of the person.

16. A downlight according to claim 1, wherein the downlight is configured to be mounted at a ceiling having a first height to the floor, wherein the controller is configured to calibrate the millimeter wave radar to operate at the first height.

17. A downlight according to claim 1, wherein the controller is further configured to determine a change in frequency between signals transmitted from the millimeter wave radar and signals received by the millimeter wave radar, and wherein the controller is configured to determine the direction of movement of the detected person based on the change in frequency.

18. A method, comprising:

detecting the presence of a person in a field of view of a millimeter wave radar embedded in a housing of the downlight;

determining a direction of movement of the detected person;

transmitting the log data to a server using a wireless transmission channel.

19. The method of claim 18, further comprising:

receiving log data from a plurality of downlights, wherein the plurality of downlights comprise the downlights;

determining a number of people inside a building based on the log data from the plurality of downlights; and

controlling the brightness of light generated by the plurality of downlights based on the determined number of people inside the building.

20. The method of claim 19, further comprising: dimming the downlight when the determined number of people inside the building is below a threshold.

21. The method of claim 19, further comprising: controlling operation of an air conditioner of the building based on the determined number of people inside the building.

22. The method of claim 18, further comprising:

receiving data from a pressure sensor located at a window or door of the building; and

controlling the brightness of light produced by the downlight based on data received from the pressure sensor.

23. A method, comprising:

determining whether a person is entering or exiting a building using millimeter wave radar embedded in respective housings of respective down lamps of a plurality of down lamps located at an entrance to the building;

calculating a first number of people entering the building during a first time period;

calculating a second number of people who left the building during the first period of time; and

controlling the brightness of light generated by the plurality of downlights based on the first number of people and the second number of people.

24. The method of claim 23, further comprising:

storing the first number and the second number in a database; and

estimating the number of people entering or leaving the building based on data from the database.

25. The method of claim 23, further comprising:

storing the first number and the second number in a database; and

determining peak hours of personnel traffic based on data from the database.

26. The method of claim 25, further comprising:

accessing the database using an electronic device via the internet; and

displaying the peak hours in the electronic device.